The use of magnetic resonance imaging (MRI) as a diagnostic tool is a fairly recent innovation in the medical field.
In MRI scanning, the MRI apparatus operates as a large magnet wherein the protons align with the strong magnetic field but are easily disturbed by a brief radio frequency pulse of very low energy so as to alter their alignment. As the protons return to their orientation with the magnetic field, they release energy of a radio frequency that is strongly influenced by the biochemical environment. The released energy is detected and mathematically analyzed for display as a two dimensional proton density image according to the signal intensity of each tissue.
The potential dangers associated with MRI scanners include a strong magnetic field within the apparatus and surrounding area. The magnetic force may convert loose iron, steel and other metal objects into unguided missiles directed at the MRI apparatus and striking personnel within the vicinity of an MRI apparatus, when these objects have been unwittingly introduced into the magnetic field of the MRI system. It is well known in the art that MRI devices are usually located within a shielded room for improved results and also to lessen the impact of the device on surrounding operations. However, the problem persists of metal objects being negligently introduced into the magnetic field by personnel entering the room or the extended magnetic field of the MRI apparatus.
It therefore remains a long felt and unmet need to provide an apparatus having an MRI shield for MRI devices in order to prevent the introduction of iron, steel and other metal objects into the magnetic field of an MRI apparatus.